10
MAN - BBR2S - REV: Original | C. System Overview
Resistance Temperature Detector (RTD)
The RTD is a platinum measuring device that measures the cooling fluid bath temperature and relays the
information to the computer control system software. It is mounted on the load frame directly under the test
specimen supports. The RTD must be calibrated at two points. One point must be calibrated at 0
°
C and the second
at the testing temperature or beyond it (at least -10
°
C or lower). The RTD is factory-calibrated at 0
°
C and -36.0
°
C. No
further adjustment should be made under normal operating conditions.
Computer Control System Software
The computer control system software provides user control of the BBR2S system in a Windows® environment with
keyboard and/or mouse access to these functions. The software provides pull-down menus, button selections, and
data entry text boxes for easy updates and access to information.
The software is designed to run on a standard PC which is connected to the base unit. During operation, the
software collects and records the data from the various sensors on the load frame. During tests, the software
controls specimen loading and unloading. The software is organized so all of the information required to conduct a
particular test is stored in the PC. This design allows future enhancements or new releases to be easily added to the
existing system without the need for hardware additions or modifications.
Mechanical Refrigeration Unit
The refrigeration unit is an immersion cooler designed as a cooling source for sub-ambient work in liquid baths.
The unit rests on the floor and maintains the cooling fluid at a constant temperature by use of the unit’s temperature
controller and the magnetic stirrer located in the bath. The single stage refrigeration system is equipped with one
compressor. A hose carries refrigerant through the cooling probe located in the bath.
Refer to the manufacturer’s literature for more detailed information regarding safety, operation, and maintenance of
the refrigeration unit.
WARNING: Refrigeration unit will cause the test bath to be extremely cold. Do not submerge
hand or arm into the test bath. Do not attempt to pull the drain plug when the test bath level is
high and the temperature is extremely cold. Extremely cold fluid may cause frostbite.
Accessories
• Specimen Molds:
Used to create specimens. Each mold consists of five aluminum bars of various
sizes, three mylar strips, and two holding rings. Five of these molds are supplied with the BBR2S.
•
Confidence Beam:
A thin, stainless steel beam of known stiffness. This beam is placed on the
specimen supports of the load frame during the confidence check.
• Non-Compliant Beam:
A length of stainless steel that has the same dimensions as the specimen.
This beam is placed on the specimen supports when verifying and calibrating the load cell and when
performing the compliance test.
• Step Disk:
The step disk is used during LVDT standardization and verification. It has five positions
containing high precision balls. The calibration positions include a zero gaging and four subsequent
steps which decrease in increments of 1, 3, 5, and 6 mm. These steps are labeled on the disk using
